Gas. For hydrogen to become a liquid, you need to cool it down to 20.28 K, which is -252.87 degrees Celcius, or -434.45 degrees Fahrenheit if that is more your style. 6 people found this useful.
Princeton's WordNet(0.00 / 0 votes)Rate this definition: 1  voice, sound, vocalize, vocalise(verb) utter with vibrating vocal chords. 2  vocalize, vocalise(verb) sing (each note a scale or in a melody) with the same vowel. 3  vocalize, vocalise, vowelize, vowelise(verb) pronounce as a vowel.
See-voc-. 1  of, relating to, or produced with the voice:the vocal sounds. 2  Music and Danceintended for singing:vocal music. 3  willing to express oneself in words, esp. in many words or insistently; outspoken:a vocal advocate of reform. 4  Phoneticsa vocal sound. 5  a musical piece for a singer; 6  song. 7  a performance of such a piece.